Users who load a function of a black box or a rear camera on a vehicle for preventing an accident risk, convenience in parking, and the like increase.
As a result, in recent years, an around view monitor (AVM) system has been developed, in which as if a total of four cameras look down from the top of the vehicle by installing cameras at front and rear sides and left and right sides of the vehicle, four images are output to a display.
The AVM system is designed to so as for a user to conveniently observe surroundings through a monitor mounted on the front side of the vehicle by compositing images acquired from cameras installed at four sides of the vehicle.
However, in the conventional AVM system, the user cannot feel naturalness because a composite image is not smooth due to different brightness of photographed images of the respective cameras installed in the vehicle.
Since an image compositing and displaying method of an on-board camera proposed in Japanese Patent Laid-Open No. 2010-187161 calculates image brightness by an average value of all pixels that belong to an image, an error in a brightness average value or a gain occurs due to other objects or a shadow, and as a result, it is difficult to accurately correct brightness.
Japanese Patent Laid-Open No. 2010-187161 (Application date, Feb. 12, 2009)